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-rw-r--r--include/llvm/CodeGen/SlotIndexes.h6
-rw-r--r--lib/CodeGen/SplitKit.cpp23
-rw-r--r--test/CodeGen/X86/2012-01-10-UndefExceptionEdge.ll155
3 files changed, 180 insertions, 4 deletions
diff --git a/include/llvm/CodeGen/SlotIndexes.h b/include/llvm/CodeGen/SlotIndexes.h
index 19bcb92f01..774a0f5443 100644
--- a/include/llvm/CodeGen/SlotIndexes.h
+++ b/include/llvm/CodeGen/SlotIndexes.h
@@ -208,6 +208,12 @@ namespace llvm {
return A.lie.getPointer() == B.lie.getPointer();
}
+ /// isEarlierInstr - Return true if A refers to an instruction earlier than
+ /// B. This is equivalent to A < B && !isSameInstr(A, B).
+ static bool isEarlierInstr(SlotIndex A, SlotIndex B) {
+ return A.entry().getIndex() < B.entry().getIndex();
+ }
+
/// Return the distance from this index to the given one.
int distance(SlotIndex other) const {
return other.getIndex() - getIndex();
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index 9dc5c21931..379025b5a9 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -62,13 +62,14 @@ SlotIndex SplitAnalysis::computeLastSplitPoint(unsigned Num) {
const MachineBasicBlock *MBB = MF.getBlockNumbered(Num);
const MachineBasicBlock *LPad = MBB->getLandingPadSuccessor();
std::pair<SlotIndex, SlotIndex> &LSP = LastSplitPoint[Num];
+ SlotIndex MBBEnd = LIS.getMBBEndIdx(MBB);
// Compute split points on the first call. The pair is independent of the
// current live interval.
if (!LSP.first.isValid()) {
MachineBasicBlock::const_iterator FirstTerm = MBB->getFirstTerminator();
if (FirstTerm == MBB->end())
- LSP.first = LIS.getMBBEndIdx(MBB);
+ LSP.first = MBBEnd;
else
LSP.first = LIS.getInstructionIndex(FirstTerm);
@@ -89,10 +90,24 @@ SlotIndex SplitAnalysis::computeLastSplitPoint(unsigned Num) {
// If CurLI is live into a landing pad successor, move the last split point
// back to the call that may throw.
- if (LPad && LSP.second.isValid() && LIS.isLiveInToMBB(*CurLI, LPad))
- return LSP.second;
- else
+ if (!LPad || !LSP.second || !LIS.isLiveInToMBB(*CurLI, LPad))
+ return LSP.first;
+
+ // Find the value leaving MBB.
+ const VNInfo *VNI = CurLI->getVNInfoBefore(MBBEnd);
+ if (!VNI)
return LSP.first;
+
+ // If the value leaving MBB was defined after the call in MBB, it can't
+ // really be live-in to the landing pad. This can happen if the landing pad
+ // has a PHI, and this register is undef on the exceptional edge.
+ // <rdar://problem/10664933>
+ if (!SlotIndex::isEarlierInstr(VNI->def, LSP.second) && VNI->def < MBBEnd)
+ return LSP.first;
+
+ // Value is properly live-in to the landing pad.
+ // Only allow splits before the call.
+ return LSP.second;
}
MachineBasicBlock::iterator
diff --git a/test/CodeGen/X86/2012-01-10-UndefExceptionEdge.ll b/test/CodeGen/X86/2012-01-10-UndefExceptionEdge.ll
new file mode 100644
index 0000000000..832a8eb814
--- /dev/null
+++ b/test/CodeGen/X86/2012-01-10-UndefExceptionEdge.ll
@@ -0,0 +1,155 @@
+; RUN: llc < %s -disable-fp-elim
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32-S128"
+target triple = "i386-apple-macosx10.7"
+
+; This test case has a landing pad with two predecessors, and a variable that
+; is undef on the first edge while carrying the first function return value on
+; the second edge.
+;
+; Live range splitting tries to isolate the block containing the first function
+; call, and it is important that the last split point is after the function call
+; so the return value can spill.
+;
+; <rdar://problem/10664933>
+
+@Exception = external unnamed_addr constant { i8*, i8* }
+
+declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
+
+define void @f(i32* nocapture %arg, i32* nocapture %arg1, i32* nocapture %arg2, i32* nocapture %arg3, i32 %arg4, i32 %arg5) optsize ssp {
+bb:
+ br i1 undef, label %bb6, label %bb7
+
+bb6: ; preds = %bb
+ %tmp = select i1 false, i32 0, i32 undef
+ br label %bb7
+
+bb7: ; preds = %bb6, %bb
+ %tmp8 = phi i32 [ %tmp, %bb6 ], [ 0, %bb ]
+ %tmp9 = shl i32 %tmp8, 2
+ %tmp10 = invoke noalias i8* @_Znam(i32 undef) optsize
+ to label %bb11 unwind label %bb20
+
+bb11: ; preds = %bb7
+ %tmp12 = ptrtoint i8* %tmp10 to i32
+ %tmp13 = bitcast i8* %tmp10 to i32*
+ %tmp14 = shl i32 %tmp8, 2
+ %tmp15 = getelementptr i32* %tmp13, i32 undef
+ %tmp16 = getelementptr i32* %tmp13, i32 undef
+ %tmp17 = zext i32 %tmp9 to i64
+ %tmp18 = add i64 %tmp17, -1
+ %tmp19 = icmp ugt i64 %tmp18, 4294967295
+ br i1 %tmp19, label %bb29, label %bb31
+
+bb20: ; preds = %bb43, %bb41, %bb29, %bb7
+ %tmp21 = phi i32 [ undef, %bb7 ], [ %tmp12, %bb43 ], [ %tmp12, %bb29 ], [ %tmp12, %bb41 ]
+ %tmp22 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ catch i8* bitcast ({ i8*, i8* }* @Exception to i8*)
+ br i1 undef, label %bb23, label %bb69
+
+bb23: ; preds = %bb38, %bb20
+ %tmp24 = phi i32 [ %tmp12, %bb38 ], [ %tmp21, %bb20 ]
+ %tmp25 = icmp eq i32 %tmp24, 0
+ br i1 %tmp25, label %bb28, label %bb26
+
+bb26: ; preds = %bb23
+ %tmp27 = inttoptr i32 %tmp24 to i8*
+ br label %bb28
+
+bb28: ; preds = %bb26, %bb23
+ ret void
+
+bb29: ; preds = %bb11
+ invoke void @OnOverFlow() optsize
+ to label %bb30 unwind label %bb20
+
+bb30: ; preds = %bb29
+ unreachable
+
+bb31: ; preds = %bb11
+ %tmp32 = bitcast i32* %tmp15 to i8*
+ %tmp33 = zext i32 %tmp8 to i64
+ %tmp34 = add i64 %tmp33, -1
+ %tmp35 = icmp ugt i64 %tmp34, 4294967295
+ %tmp36 = icmp sgt i32 %tmp8, 0
+ %tmp37 = add i32 %tmp9, -4
+ br label %bb38
+
+bb38: ; preds = %bb67, %bb31
+ %tmp39 = phi i32 [ %tmp68, %bb67 ], [ undef, %bb31 ]
+ %tmp40 = icmp sgt i32 %tmp39, undef
+ br i1 %tmp40, label %bb41, label %bb23
+
+bb41: ; preds = %bb38
+ invoke void @Pjii(i32* %tmp16, i32 0, i32 %tmp8) optsize
+ to label %bb42 unwind label %bb20
+
+bb42: ; preds = %bb41
+ tail call void @llvm.memset.p0i8.i32(i8* %tmp32, i8 0, i32 %tmp9, i32 1, i1 false) nounwind
+ br i1 %tmp35, label %bb43, label %bb45
+
+bb43: ; preds = %bb42
+ invoke void @OnOverFlow() optsize
+ to label %bb44 unwind label %bb20
+
+bb44: ; preds = %bb43
+ unreachable
+
+bb45: ; preds = %bb57, %bb42
+ %tmp46 = phi i32 [ %tmp58, %bb57 ], [ 255, %bb42 ]
+ %tmp47 = icmp slt i32 undef, 0
+ br i1 %tmp47, label %bb48, label %bb59
+
+bb48: ; preds = %bb45
+ tail call void @llvm.memset.p0i8.i32(i8* %tmp32, i8 0, i32 %tmp9, i32 1, i1 false) nounwind
+ br i1 %tmp36, label %bb49, label %bb57
+
+bb49: ; preds = %bb49, %bb48
+ %tmp50 = phi i32 [ %tmp55, %bb49 ], [ 0, %bb48 ]
+ %tmp51 = add i32 %tmp50, undef
+ %tmp52 = add i32 %tmp50, undef
+ %tmp53 = getelementptr i32* %tmp13, i32 %tmp52
+ %tmp54 = load i32* %tmp53, align 4, !tbaa !0
+ %tmp55 = add i32 %tmp50, 1
+ %tmp56 = icmp eq i32 %tmp55, %tmp8
+ br i1 %tmp56, label %bb57, label %bb49
+
+bb57: ; preds = %bb49, %bb48
+ %tmp58 = add i32 %tmp46, -1
+ br label %bb45
+
+bb59: ; preds = %bb45
+ %tmp60 = ashr i32 %tmp46, 31
+ tail call void @llvm.memset.p0i8.i32(i8* null, i8 0, i32 %tmp37, i32 1, i1 false) nounwind
+ br i1 %tmp36, label %bb61, label %bb67
+
+bb61: ; preds = %bb61, %bb59
+ %tmp62 = phi i32 [ %tmp65, %bb61 ], [ 0, %bb59 ]
+ %tmp63 = add i32 %tmp62, %tmp14
+ %tmp64 = getelementptr i32* %tmp13, i32 %tmp63
+ store i32 0, i32* %tmp64, align 4, !tbaa !0
+ %tmp65 = add i32 %tmp62, 1
+ %tmp66 = icmp eq i32 %tmp65, %tmp8
+ br i1 %tmp66, label %bb67, label %bb61
+
+bb67: ; preds = %bb61, %bb59
+ %tmp68 = add i32 %tmp39, -1
+ br label %bb38
+
+bb69: ; preds = %bb20
+ resume { i8*, i32 } %tmp22
+}
+
+declare i32 @__gxx_personality_v0(...)
+
+declare noalias i8* @_Znam(i32) optsize
+
+declare void @Pjii(i32*, i32, i32) optsize
+
+declare i32 @llvm.eh.typeid.for(i8*) nounwind readnone
+
+declare void @OnOverFlow() noreturn optsize ssp align 2
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-28 05:31:46 +0000